But a Families SA social worker told the woman she was a “paranoid mother”, according to the newspaper.

The mother was reportedly told in July that police had identified her child as one of seven children allegedly abused by a Families SA carer at a residential facility.

The minister, Jennifer Rankine, said at the time that there had been no concerns raised about the 32-year-old man before his arrest. It has since emerged that a co-worker referred allegations of inappropriate behaviour to police about a year before the arrest.

South Australia’s police commissioner, Gary Burns, confirmed last week that police had chosen not to investigate at the time, believing there was not “anything concrete enough” to proceed.

It has also been reported that concerns were raised about an aspect of the man’s psychometric testing.

Rankine said on Wednesday that she was unable to comment on the latest allegations because they could prejudice investigations. “I was clearly advised that there was nothing recorded in his criminal history and there were no child protection notifications that had been made about him at the point of his employment,” she told ABC Radio.

“I have consistently said, and I repeat again, I cannot talk about anything to do with issues that have been raised since his employment.”

The opposition has accused the minister of evading scrutiny by refusing to provide details about previous allegations.

The man also is charged with the production, possession and dissemination of child exploitation material after police said they found more than 100,000 still images and 600 video files.